diff --git a/doc/api_docs_reference.md b/doc/api_docs_reference.md
index 6cdd20eaac96faf73ecf7bca2cae20d3ea219ea6..ec7a5dcc0848bef5f06f20532039bc471e6c45fe 100644
--- a/doc/api_docs_reference.md
+++ b/doc/api_docs_reference.md
@@ -119,7 +119,6 @@ int32_t ubturbo_ham_migrate(HamRamPages *ramList, size_t ramNum, int32_t step);
 | ERR_MIGRATE_PAGES    | 页面迁移失败      |
 | ERR_MODIFY_PAGETABLE | 修改页表属性失败    |
 | ERR_CLEAR_CACHE      | 刷cache失败    |
-| ERR_DRAIN_UB         | 执行UB排空失败    |
 
 ## 约束 CONSTRAINTS
 
diff --git a/src/ham.c b/src/ham.c
index 2a8861638274607b7c8d046bdcc116ec5a9e0dfc..80be2a7f5b51d2276ccc56e2dabc6dc4ecf9efe9 100644
--- a/src/ham.c
+++ b/src/ham.c
@@ -154,11 +154,6 @@ int32_t ubturbo_ham_migrate(HamRamPages *ramList, size_t ramNum, int32_t step)
             HAM_LOGERROR("Failed to cache clear, errno: %d.\n", errno);
             return -ERR_CLEAR_CACHE;
         }
-        ret = HandleIoctl(g_fd, HAM_UB_DRAIN, (uintptr_t) &g_scna);
-        if (ret) {
-            HAM_LOGERROR("Failed to drain ub, errno: %d.\n", errno);
-            return -ERR_DRAIN_UB;
-        }
     }
 
     return SUCCESS;
diff --git a/src/ham.h b/src/ham.h
index c65df1c870acef9388cf3ec486ad1848df92cc16..e1f428ad6717b4de70d098b020c3bf97bd7a7716 100644
--- a/src/ham.h
+++ b/src/ham.h
@@ -31,7 +31,6 @@ enum HamErrCode {
     ERR_MIGRATE_PAGES = 0x4000,
     ERR_MODIFY_PAGETABLE = 0x4001,
     ERR_CLEAR_CACHE = 0x4002,
-    ERR_DRAIN_UB = 0x4003,
     ERR_ROLLBACK_PAGES = 0x5000,
 };
 
diff --git a/src/ham_comm.h b/src/ham_comm.h
index 2ca17e24b18f2e8293d5b79dcc9bb0fffefdb5df..7e387ba5e426d69057f4e2523a7c16bd12fd5e0a 100644
--- a/src/ham_comm.h
+++ b/src/ham_comm.h
@@ -31,7 +31,6 @@ extern "C" {
 #define HAM_STOP_MIGRATION _IOW('N', 3, unsigned long)
 #define HAM_MODIFY_PAGETABLE _IOW('N', 4, unsigned long)
 #define HAM_CACHE_CLEAR _IOW('N', 5, unsigned long)
-#define HAM_UB_DRAIN _IOW('N', 6, unsigned long)
 
 typedef enum {
     HAM_LOG_DEBUG = 0,
diff --git a/test/cases/test_ham.cpp b/test/cases/test_ham.cpp
index 48a3109b75fe6819ff0bb2f4268a6e577f0f155b..af09f1116b544b4f7676f3623ef3b9c4f37125e5 100644
--- a/test/cases/test_ham.cpp
+++ b/test/cases/test_ham.cpp
@@ -134,12 +134,6 @@ TEST_F(TestHam, migratePagesTask)
     ret = ubturbo_ham_migrate(nullptr, 0, HAM_MIGRATE_COMPLETION);
     EXPECT_EQ(ret, -ERR_CLEAR_CACHE);
 
-    /* drain ub failed */
-    MOCKER(HandleIoctl).stubs().with(eq(g_fd), eq(HAM_UB_DRAIN), any()).will(returnValue(-1))
-        .then(returnValue(0));
-    ret = ubturbo_ham_migrate(nullptr, 0, HAM_MIGRATE_COMPLETION);
-    EXPECT_EQ(ret, -ERR_DRAIN_UB);
-
     /* all success */
     ret = ubturbo_ham_migrate(nullptr, 0, HAM_MIGRATE_COMPLETION);
     EXPECT_EQ(ret, SUCCESS);